1. Field of the Invention
This invention relates to an apparatus for storing and retrieving microfiche cards and one aspect of the invention is a device for separating cards stored in closely adjacent position in a tray to afford access to a predetermined card.
2. Description of the Prior Art
Storing a plurality of microfiche and retrieving a single microfiche to display individual images and project the same either on a screen, make a hard copy of the image, or position the microfiche such that a video signal may be generated by scanning the film for projection on a remote terminal is being practiced by commercial equipment. Examples of patents disclosing a microfiche retrieval system of the type addressed herein are U.S. Pat. Nos. 3,429,436, issued Feb. 25, 1969 to E. H. Irasek; 4,190,899, issued Feb. 26, 1980 to D. H. Smith et al; and 4,273,427, issued June 16, 1981 to D. C. Bailey. Numerous additional patents exist relating to devices for scanning microfiche or other microfilm image-supporting media such that the information on the microfilm image may be retrieved and reread by a projection image or by duplication on a CRT terminal. Examples of such devices are illustrated in U.S. Pat. Nos. 3,753,240, issued Aug. 14, 1973 to Roy L. Merwin; and 3,604,850, issued Sept. 14, 1971 to R. R. Eckenbrecht et al.
These systems provide a means for storing information which must be stored on a photographic medium and retrievable automatically by suitable coding logic stored in a computer. The actual storage and retrieval device will respond to the signals to rotate the storage file to locate the predetermined microfiche card at the retrieval opening such that it may be removed from the file and a specific image on the card positioned for reading the image either by projection, by scanning, or by copying.
The present invention thus deals with the file for storing the microfiche cards. The apparatus for separating the cards in the file to allow a selected card to be drawn from the file and positioned at the film reading station varies with different apparatus but is very important to permit a selected card to be withdrawn and reinserted in the file.
The mechanism utilized for storing the microfiche card comprises a tray, fixed on a rotatable axis and positionable to place a given one of the storage slots at the access opening. Picker fingers then grasp the microfiche card, lift the card slightly off the tray, straighten (by tensioning) the leading edge of the card and withdraw it from the file. Separators separate and hold the adjacent cards from the selected card so that card can be readily grasped, so there is no tendency for the adjacent cards to drift outward along with the selected card, and to permit the return of the selected card without collision. The removed card is positioned at the viewing station. Thus, the visual patterns stored in the microfiche card can be optically scanned to convert the image pattern electrically to signals which by analog-to-digital conversion and speed conversion are transmitted to remote terminals along with alphanumeric data for review by an operator. The equipment of this invention will make visual patterns stored on-line in a control system totally computer driven and accessible. When the information has been viewed the microfiche card is reinserted into the slot in the tray and the separators for the adjacent microfiche cards are returned to their normal position and the tray carousel is rapidly indexed to locate the next microfiche card called for by the computer.
During insertion of the microfiche cards, which are four to eight mils in thickness and quite susceptible to bending or buckling during mechanical handling of the microfiche cards, the cards may become damaged or destroyed. It is therefore important the equipment handle the cards in a manner to guide the card into the tray as much as possible when the card is reinserted and to hold adjacent cards so they do not have the ability to drift outward when a selected card is being withdrawn.
The prior art has utilized numerous devices for precisely positioning a microfiche card in a storage tray to permit the card to be retrieved from the tray and returned to the tray. U.S. Pat. No. 3,429,436 discloses a microfiche card storage and retrieval device wherein each of the microfiche cards are provided with an edge strip to hold an edge of the card in a rigid position within the storage device. When a predetermined card is selected the selected card will be stopped adjacent the center of a delivery station. The adjacent cards are separated by a pair of wedges. The wedges move under the urging of rotatable cam plates which move the wedges away from the carousel and toward each other. Then the wedges numbered 147 move inwardly past the edges of the cards on either side of the selected card and as the plates continue to rotate, the wedges are moved apart to move all of the cards away from the selected card and against the bias of two springs 150A away from rigidly mounted opposed plates 150B in the drum which serves to support the cards. The separation of the neighboring cards from the preselected card thus permits withdrawal and reinsertion of the card. The effect is to be continually moving all the cards relative to the trays each time the selected card is to be withdrawn.
The present invention provides a card storage system utilizing a pair of circular trays each formed with verically spaced opposed grooves for receiving opposite edges of a microfiche card. A card is located by the position of that card in the drum. Rotation of the drum a predetermined number of steps positions a card precisely at the retreval station. At the retrieval station the card can then be retrieved without interferring with the other cards except the cards adjacent the selected card are bowed at the center portions thereof to separate them from the selected card.
The present invention thus solves the problem of having all of the cards being moved transversely of their position in the tray as selected cards are retrieved. It further does not require that a storage tray be filled to any predetermined amount before the system can be utilized to store and retrieve microfiche cards. It affords storage of cards made of thin film material, and it affords reliable retrieval of cards of thin material which do not have a support strip on any edge.